My filly is changing colour?

Our mare is a deep Sorrel all summer long then a honey Palomino in the winter . She was born a solid Appaloosa and at 12 yrs old she got chocolate spots on her rump no white blanket just darker spots on a dark body , her yearling colt is a dark black bay with black spots and no white blanket ? Its hard to say what you will get just enjoy the show .